Field of the Invention
The invention relates to a controller for a motor vehicle with an automatic transmission, which is connected to sensors in the transmission, wherein a gear ratio is varied with actuators for actuating final control elements in the transmission; the transmission is constructed as an integrated complete system which includes all mechanical, hydraulic and electronic transmission components; and the control unit is provided with a plug that is connected to a printed circuit board on which electronic components of a transmission controller are mounted.
Such controllers are used in motor vehicles with automatic transmissions and include an electronic transmission controller which is connected to an engine controller through a communications channel or other communications path. The controller, or parts thereof, may also be combined with the transmission controller in a unit. The transmission controller evaluates information from the engine controller and signals from various sensors in the transmission, and optionally other sensors in the motor vehicle, and outputs control signals to actuators of the transmission, by which friction elements are actuated and thus switching operations are performed, or by which the gear ratio is varied, in the case of continuously variable transmissions.
In a known transmission control system, electrical, mechanical, hydraulic and electronic control devices are disposed inside the transmission housing. A printed circuit board, which is partly surrounded by oil, carries control electronics, according to German Utility Model DE 93 07 228.7 U1. Gaining access to the control system, for instance for repairs, requires opening or removing the entire transmission housing.
In a known controller for a motor vehicle, the transmission controller is secured to the transmission housing, the coils of the electrohydraulic pressure control valves are integrated with the transmission controller, and sensor signals are transmitted wirelessly to the transmission controller, according to German Patent DE 43 34 595 C.